Yarn control means for circular knitting machines



April 15, 1969 w. H. IMBODEN 3,438,225 YARN CONTROL MEANS FOR CIRCULAR KIHTTlNG MACHINES Filed Oct. 14, 1966 Sheet of 2 April 5, 1969 w. H. IMBODEN 3,438,225

YARN'CONTROL MEANS FOR CIRCULAR KNITTING MACHINES Filed Oct. 14,1966 Sheet 2 of 2 Feed 3 Feed 1V0.

United States Patent 3 438,225 YARN CONTROL MEANS FOR CIRCULAR KNITTING MACHINES Walter H. Imboden, Reading, Pa., assignor to North American Rockwell Corporation, Pittsburgh, 1321., a corporation of Delaware Filed Oct. 14, 1966, Ser. No. 586,723

Int. Cl. D041) 15/60 US. Cl. 66-125 2 Claims ABSTRACT OF THE DISCLOSURE A member positioned between yarn guide means and a pair of yarn feed fingers of a knitting machine, the member being movable to form a bight in the yarn of each finger to provide an increased length of yarn between the guide means and feed finger when the feed finger 1s in feeding position and to release the bight to permit the extra yarn to be drawn into and held by suction means associated with yarn severing means of the machine when the yarn is severed and the feed finger is in inactive position.

The instant invention relates to circular knitting ma chines particularly those employed to knit ladies fine gauge seamless hosiery and is directed to the solution of problems encountered in such machines during the making of yarn changes as for example from main to reinforcing yarns and vice versa.

Circular knitting machines now employed in the production of womens hosiery conventionally embody means for holding the ends of out of action yarns in an air stream set up in a suction tube or foot having a yarn receiving mouth adjacent but spaced from the dial of the machine. Due to features of the dial and the apparatus carried thereby the yarn cutter or trimmer, which is adapted to sever the yarns adjacent the fabric upon yarn changes, is most conveniently located adjacent the leading end of the foot.

Particularly in certain multifeed machines it has been found necessary to position a suction foot and its associated cutter closely adjacent one of the yarn feeds for controlling the yarns at that feed. In operation, as for example in the substitution of reinforcing and main yarns at such feed, the yarn finger of the yarn which is to be removed from action is raised to nonfeeding position the yarn fed thereby being carried, as the needle cylinder continues to rotate, beneath the mouth of the suction foot and to the cutter where the yarn is severed. The severed end of the yarn leading from the yarn finger is then caught up in the air stream and carried into the suction tube to be held therein until the yarn is to be reintroduced to the knitting action. Where as mentioned above the suction foot and cutter employed therewith are closely adjacent the yarn feed the length of yarn drawn into the foot is relatively short. Consequently the air stream does not necessarily have a sufiicient grasp on the yarn to insure its retention particularly during the return of the yarn finger to active position and the initial drawing of the yarn by the first needles to take it. Thus the abrupt pull on the yarn as its feed finger moves to its operative position and the initial demand for the yarn by the needles tend to withdraw the relatively lightly held yarn end from the suction foot rather than draw additional yarn through the tension device from the supply pirn. Loss of control of the yarn end before the initial stitches are formed and the yarn is tied into the fabric results in a press-off or termination of the knitting action and consequently a waste fabric.

3,438,225 Patented Apr. 15, 1969 Heretofore it has been attempted to overcome the afore-' mentioned problem by providing a movable member operable at the time of yarn change to draw an additional length of yarn in the form of a bight between the feed finger and the fabric. Upon return of the member to its original position following severance of the yarn the additional yarn thus provided was drawn into the suction tube permitting the air stream to maintain a better grasp thereon. The prior proposal has not however provided an adequate solution to the problem particularly in that the location of the movable member as described above greatly limits the size of the bight of yarn which may be drawn with the result that the extra length of yarn is insufiicient to enable the air stream in the suction tube to grasp it to the extent necessary to ensure its retention. Also in drawing the bight of the yarn to be taken out of action a similar bight is necessarily drawn in any other inactive yarn or yarns held by the air stream in the suction foot tending to withdraw such yarn therefrom.

The principal object of the instant invention is the provision of improved means, overcoming the above noted objections of prior proposals, by which an extra length of yarn is provided for retention by the air stream in the suction foot.

Another object of the invention is the provision of means attaining the above stated object and comprising a movable arm located to act on the yarn between the feed finger and the yarn pirn or other supply whereby due to the absence of limiting factors a greater length of yarn may be drawn than heretofore to insure a sufficient length of yarn in the suction tube for retention by the air stream therein.

A further object of the invention is the provision of means as defined above so constructed that the drawing of a bight of the yarn to be taken out of action does not interfere with other yarn extending from a supply to the feed station. A still further object of the invention is the provision in such device of means whereby the device is adapted to selectively draw a bight in either of two yarns.

The invention will be more fully understood and further objects and advantages thereof will become apparent when reference is made to the more detailed description to follow and to the accompanying drawings in which:

FIG. 1 is an elevational view of a portion of a circular knitting machine illustrating the invention applied thereto;

FIG. 2 is a top plan view on an enlarged scale of the knitting machine head illustrated in FIG. 1;

FIG. 3 is a top plan view of certain other mechanisms illustrated in FIG. 1; and

FIG. 4 is a sectional view on an enlarged scale taken on the line 4-4 of FIG. 3 looking in the direction indicated by the arrows.

Referring now to the drawings there is shown a portion of a known circular knitting machine of the type employed to knit womens hosiery, the machine including the usual latch ring 10 and dial 11 comprising a rotatable dial bed 13 and a stationary dial cap 14. Needles 15 are slidably carried in slots in the usual rotatable needle cylinder 16.

The machine illustrated is a multifeed machine (see FIG. 2) of a type which presents the problem solved by the present invention. As will be noted the feeds, numbered from 1 to 4, include three feeds, namely Feeds Nos. 1, 2 and 3, which are relatively closely grouped with the remaining feed, Feed No. 4, spaced from the others. 'Iwo pneumatic meansfindicated generally at 20 and 21 are employed for holding the ends of idle yarns. Yarn holding means 20 comprises a tube 22 connected to any suitable source (not shown) of continuous suction and a foot 23 extending opposite Feeds Nos. 1, 2 and 3 and defining a mouth spaced from the dial to permit ingress of the air drawn through the tube and hence of yarn ends carried thereby. The other yarn holding means 21 comprising a suction tube 24 similarly connected with the suction source and having a foot 25 serves the remaining feed, Feed No. 4.

The yarn severing means employed is generally of the type shown in US. patent to J. D. Moyer No. 3,222,892, issued Dec. 14, 1965, and includes an annular member 26 carried by the dial bed 13 for rotation therewith. Annular member 26 is provided with teeth 27 at its outer periphery which are pitched in the direction of the counterclockwise or rotary movement of the needle cylinder and dial bed. Cutting elements 28 and 29 are secured to the dial cap in any suitable way adjacent the leading edges of the feet 23 and 25 of the yarn holding means 20 and 21, respectively, the cutting elements cooperating with the upper surfaces of the teeth of annular member 26 to sever the yarns fed from the several stations close to the circle of needles at the time the fingers for the yarns are moved to inactive positions and again when the fingers are returned to active positions.

Referring particularly to FIG. 1 the knitting machine includes the usual yarn rack indicated generally at 32 supported at the back of the machine frame by a plurality of uprights one of which is shown at 33. The yarn rack carries a plurality of pirns of yarn 34 such as main and reinforcing yarns for the several feed stations and also supports a conventional yarn tensioning means of any suitable types, indicated diagrammatically at 35, for each yarn. In front of the yarn rack and generally overlying the dial of the knitting machine is a substantially circular plate 36 (FIG. 3) having a rim portion 37 of reduced thickness the plate being supported by a preferably integral arm from a post 38 which in turn is supported from the machine frame. Plate 36 carries a plurality of yarn guide eyes 39. Each yarn is led from its pirn through its tension means 35 and one of the guide eyes 39, and through additional guiding means such as means 12 if desired to its yarn feed finger.

The problem solved by the instant invention occurs primarily at a yarn feed station such as Feed Station No. 3 f the machine disclosed and particularly in connection with the main and reinforcing yarn fed at that station. Such station includes a plurality of yarn feed fingers, three fingers 40, 41 and 42 being shown, the fingers being adapted to be moved by suitable pattern means (not shown) between a lowered yarn feeding position as illustrated for finger 41 and a rest or inoperative position as illustrated for fingers 40 and 42. It will be assumed for the purpose of the description of the invention which follows that a main yarn Y]; is being supplied by yarn feed finger 40 and a reinforcing yarn Y-2 is being supplied by yarn feed finger 41, the yarns leading from their respective pirns through their tension means 35 and through a spaced pair of the guide eyes 39, designated 39a and 3% (FIGS. 3 and 4) to guide means 12 and to their feed fingers. As will be observed from FIG. 2 in view of the adjacent relationship of the yarn feed fingers 40 and 41 at Feed Station No. 3 to the foot 23 of yarn holding means 20 and to the associated cutting element 28 the length of yarn which would normally be drawn into the yarn holding device to be held thereby upon the removal of a yarn from knit ting action by the raising of one of the fingers is relatively short presenting the possibility of the end being withdrawn particularly when it is again fed to the needles as previously explained.

In accordance with the instant invention means are provided operative while the feed finger is in its active feeding position to draw a bight in the yarn extending between its pirn and its feed finger. Further the invention includes means to restore the bight forming means to its inactive position to release the extra yarn of the bight at the time of or following the movement of the feed finger for that yarn to its inactive position and severance of the yarn whereby the extra yarn provided by the bight is drawn into the yarn holding device providing a sufficient length thereof to insure its retention when the yarn feed finger is again moved into active position.

Referring now particularly to FIGS. 1, 3 and 4 the means referred to above comprises an arm 45 having a smooth yarn contacting portion 46 of reduced diameter, arm 45 being secured in an elongated hub 47. Hub 47 is pivotally mounted intermediate its ends on a pintle 48 suitably comprising, as illustrated, a bolt projecting through a bearing in the hub and screwed into a threaded perforation in plate 36 and secured by a lock nut 49. Suitably a spacer washer 50 is inserted between the hub and plate 36 to locate the hub and hence arm 45 substantially below the plate. As will be observed from FIGS. 1, 3 and 4, hub 47 and arm 45 are so located and dimensioned that portion 46 of arm 45 lies between the yarns Yl and Y2 in their passage from their respective guide eyes 39a and 39b to guides 12 adjacent the yarn feed fingers. A boss 51 is rotatably secured to a portion of hub 47 extending on the opposite side of the pivot from arm 45. Boss 51 is perforated to receive one end of link 52 the link end being secured therein by a set screw 53. Link 52, which is bent to the configuration illustrated, has its other end 54 secured in a pin 55 mounted for rotation in the outer end of an arm 56 of a lever 57. Lever 57 is pivoted as at 58 on one arm 59 of a bifurcated bracket 60, the bracket including a collar portion 61 mounted on post 38. A second arm 62 of lever 57 carries a pin 63 adjacent the end thereof and a tension spring 64 has one end secured to pin '63 and its other end secured to pin 65 on collar 61, the spring biasing lever 57 to rotate in a counterclockwise direction, as viewed in FIG. 1, on its pivot 58. A third arm 66 of lever 57 rotatably carries a conventional fitting 67 securing one end of a Bowden wire 68, the sheath of which is secured by a conventional fitting to a second arm 70 of bracket 60. The other end of bowden wire 68 is connected to an end of a pattern lever 71 pivoted as at 72 to a frame member and including a nose portion 73 adapted to ride on the surface of suitably the main cam drum 74 of the knitting machine which is adapted for step-by-step movement in the usual manner. Main cam drum 74 includes a cam ring 75 having at least one cam rise 76 on the surface thereof in the path of the nose 73 of lever 71 and also includes at least one recessed portion '77 in the path of the nose, the recessed portion defining in effect a reverse cam.

The arrangement of the parts is such that when the nose 73 of pattern lever 71 is in engagement with the normal surface of the cam ring 75 as illustrated in FIG. 1 the portion 46 of arm 45 is spaced approximately midway between yarns Y-l and Y2 as illustrated in full lines in FIG. 4. In the setting up of the machine for operation cam rise 76 is so positioned and dimensioned that upon the usual rotation of the pattern drum the cam rise will be contacted by the nose of pattern lever 71 suitably prior to the removal of yarn finger 40 from action whereby, by means of the Bowden wire 68, lever 57 and link 52 illustrated, hub 47 and arm 45 carried thereby will be rotated in a counterclockwise direction from the position shown in full lines FIG. 4 to the position to the left shown in dot-and-dash lines in that figure to draw a bight in yarn Y1 as illustrated. The extent of the swinging movement of the arm and hence the extent of the bight of yarn thus formed is controlled by the height of cam rise 76 and can be determined as desired by employing a cam rise of selected height. In the further operation of the machine and continued step-by-step movement of the pattern drum and following removal of yarn ifeed finger 40 from action and severance of the yarn, cam rise 76 being of a length correlated to the rotation of the pattern drum to achieve this purpose, nose 73 rides off the cam rise and permits arm 56 of lever 57 and link 52 to move to the left as viewed in FIG. 1 under the influence of spring 64 to rotate arm 45 in a clock-wise direction to its original neutral position thereby releasing the bight of yarn previously drawn which is sucked into the yarn holding device to increase the length of the yarn therein to such an extent that it will not be subsequently withdrawn as the yarn feed finger 40 is again moved to active position.

When the yarn Y2 is to be removed from action nose 73 rides into the recess 77 during rotation of the pattern drum 74. As a consequence through the bowden wire, lever and link, hub 47 and arm 45 are rotated in a clockwise direction to draw a bight of yarn Y-2 as illustrated by dot-and-dash lines to the right in FIG. 4. Upon continued rotation of the cam drum nose 73 of lever 71 rides out of the recess, the length of the recess being correlated to the movement of the drum to obtain the desired timing, and arm 45 is again restored to its neutral position providing the extra yarn of the bight which is drawn into the yarn holding device for retention therein. The length of additional yarns thus obtained is determined by the depth of the recess 77 which can be modified as desired.

As will be understood that while the cam means for a single removal of yarns Y1 and Y-2 from action has been illustrated additional removals of the yarns from action may be provided for by additional cams 76 and recesses 77. It will also be noted that the mechanism of the instant invention satisfies each of the several objects previously set forth particularly in that the positioning and operation of the arm 45 is such that bights of substantial length may be drawn to provide the required amount of extra yarn. Also the single arm 45 serves both yarns Y-1 and Y2 but need not interfere with any other yarns leading to the yarn lfeed under discussion, which yarns can be guided through plate 36 at points sufficiently remote from yarns Y-1 and Y-Z.

Having thus described the invention in rather complete detail it will be understood that these details need not be strictly adhered to and that various changes and modifications may be made all falling within the scope of the invention.

I claim:

1. In a circular knitting machine including a yarn -feed station, a pair of yarn feed fingers movable between active and inactive positions at said station, means for supplying yarns to said fingers, means remote from said station and between said supply means and said fingers for guiding said yarns, means for severing the yarns when said fingers are moved to inactive positions and suction means for receiving and holding said severed yarn ends, the improvement comprising means located between said fingers and said yarn guide means operable to draw bights in said yarns alternatively to provide increased lengths thereof between said fingers and guide means, and means for operating said last named means to draw such bights when said fingers are in active positions and to release said bights to provide said increased yarn lengths to be drawn into said suction means when said yarns have been severed and said fingers are in inactive positions.

2. In a knitting machine as defined in claim 1 wherein said means to draw bights in said yarns alternatively comprises an arm and means mounting said arm for swinging movement alternatively between a neutral position intermediate said yarns and a first position in which it contacts and draws a bight in the yarn of one finger of said pair of fingers and between said neutral position and a second position in which it contacts and draws a bight in the yarn of the other finger of said pair of fingers.

References Cited UNITED STATES PATENTS 3,097,513 7/1963 Pike et al. 3,147,604 9/1964 Ziem-ba 66125 3,301,015 1/1967 Eberle 66-125 3,359,759 12/1967 Mattingly et al 66-125 ROBERT R. MACKEY, Primary Examiner.

US. Cl. X.R. 66-140 

